Wikipedia:Reference desk/Archives/Science/2016 September 28

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

September 28

Were there ever any places too far from greenery for bees?

But otherwise suitable. So if you put a rooftop garden there it'll never get pollinated unless you import bees. Or someone puts a beehive between you and the nectar and within bee foraging distance of both. Sagittarian Milky Way (talk) 01:28, 28 September 2016 (UTC)

We actually have an article on bee foraging. Apparently the limit is 4km from the hive, though this can vary with temperature and strain. Someguy1221 (talk) 01:48, 28 September 2016 (UTC)

With that limited range, I wonder in there are many islands without bees. Do other pollinators, like hummingbirds, have longer ranges ? StuRat (talk) 03:34, 28 September 2016 (UTC)

Apparently not many but they do exist [1]. Bear in mind bees could be introduced once humans are involved. The relative importance and methods of pollination may vary [2] [3]. Note also even in a place like NZ how native pollinators compare to introduced ones may be something we're only beginning to understand [4] [5] [6]. Nil Einne (talk) 11:35, 28 September 2016 (UTC)

The 4-5km number is not an upper maximum though as that's just the point where they reach a net negative energy gain. Some reports list 7 or 10 miles as a maximum observed amount of honey bees. Keep in mind though that honey bees are not native here in North America at least. Kingofaces43 (talk) 18:13, 29 September 2016 (UTC)

• This article looks to have some good, relevant information for your research. --Jayron32 03:47, 28 September 2016 (UTC)

Or someone puts a beehive between you and the nectar - you realize pollen and nectar almost always come together in the inflorescence, right? This [7] is a rather good book on the general topic of pollination and ecology, including range considerations. It's available for preview on Google books.

Also, do bear in mind that there's some degree of specificity in what a bee can pollinate. So, for example, if you grow vanilla, it will not be pollinated, even if there are zillions of honey bees around. Vanilla requires a specific orchid bee, and they have never been successfully cultivated at large scale. So all vanilla grown outside of the bee's range is pollinated by human hand. Fig and fig wasp have a similar obligate specificity. Then recall that there are some flowers that are such generalists, they can be pollinated by an enormous variety of flies, bees, wasps, moths, butterflies, etc. SemanticMantis (talk) 14:12, 28 September 2016 (UTC)

The Monarch butterfly migrates up to 5,000 miles. This involves several generations, but each individual must travel a great distance and presumably could be a route of pollination. DrChrissy ^(talk) 18:06, 29 September 2016 (UTC)

Concorde jet

What's the minimum length of runway the Concorde jet needed to take off and land? (Assume sea level, standard atmosphere; takeoff is with a full load of fuel but only 3 passengers and their baggage, plus crew; landing is with the same payload but with 1 hour's worth of fuel.) 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 03:10, 28 September 2016 (UTC)

This website, Avialogs, hosts a PDF purported to be an authentic scan of an approved flight manual for a British Airways Concorde, published in 1979. Do you need help decoding the performance charts?

Many other websites host data books for Concorde models in various popular flight simulator softwares. The accuracy of those data books will vary widely, depending on how attentive to detail the authors are. It barely needs stating, but if you need correct answers, never depend on a flight manual you find on the web. Every single aircraft has exactly one legal and approved flight manual uniquely assigned to its tail number.

Nimur (talk) 03:20, 28 September 2016 (UTC)

Performance charts? I don't see any -- I see lots of system schematics, but no performance charts. 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 05:49, 28 September 2016 (UTC)

I've got say that of a cursory scan of 531 pages all I saw was push button A to kill the captain type stuff, nothing useful. Greglocock (talk) 10:43, 28 September 2016 (UTC)

By my cursory scan of three volumes of Concorde flight manuals, the required runway would be something close to 3000 feet, but this simplification is confounded by the very complex take-off roll procedure for Concorde. It is not only a very complex multi-engine air transport aircraft, but it also has unique powerplant management procedures and noise abatement procedures.

I found this flight manual published by an X-Plane enthusiast community for a simulated Concorde: California Airlines Concorde Manual. It puts the data in a format that mere mortals might find easier to read; it estimates a required take-off roll of 4000 feet; but it is a manual for a community-created software modification for personal flight simulator. Its accuracy is only trustworthy up to a point.

None of my bookshelf resources have easy-to-consume data on take-off roll for Concorde either. I can find quick statitics on the powerplant, speed, capacity, and so on,...

Concorde's performance manual listed specific airports and specific runways where operations were approved. Ths was not only due to runway length, but also for runway quality (roughness, grade, and weight bearing capacity); for departure procedure; for noise abatement; and so on. The aircraft had unique capabilities, but it wasn't well-suited for general-purpose airline service at every major airport.

Nimur (talk) 14:39, 28 September 2016 (UTC)

Excellent! So it could take off and land at Concepcion, Buenos Aires or Adelaide if desired -- say, for a one-time special rescue mission? (Or even at Tandil, if absolutely necessary?) 2601:646:8E01:7E0B:8066:7A88:8D1A:2A2B (talk) 00:07, 29 September 2016 (UTC)

Sure! Like almost everything else in aviation, there is probably some way to do it, safely and legally, if there was a pilot crazy enough to put the effort into it. And who's gonna pay for the fuel?

Nimur (talk) 03:47, 29 September 2016 (UTC)

In my case, it will be virtual fuel (see below), so I think I'll let Lord Glenarvan foot the bill for the entire operation (also see below) ;-) 2601:646:8E01:7E0B:8066:7A88:8D1A:2A2B (talk) 06:35, 29 September 2016 (UTC)

While you're "airborne," see if you can spot Lincoln Island... it should be air-accessible, and its leader is an Army captain, a railroader, an engineer, and some kind of scientist.

And be sure to practice your virtual radio skills when you're flight-simming: here's the Radio Communications Phraseology and Techniques (though for your mission, you might want to review ICAO radio procedures too!) This is a great chance to build up experience in your use of the radio, long before you ever key a (non-simulation) transmitter.

Nimur (talk) 14:34, 29 September 2016 (UTC)

That could be a bonus objective -- but there's no need for an airport at Lincoln Island, because for the last part of the mission the player will be flying not the Concorde but a flying boat or an ekranoplane (also see below). In fact, there will be several aircraft used during the mission: Grumman Goose from Glasgow to Glenarvan's yacht and then to Heathrow; Concorde from Heathrow to Concepcion; Maule M-7 from Concepcion to Buenos Aires via the Antuco Pass, Las Ovejas and Tandil; Concorde again from Buenos Aires to Adelaide; light aircraft (I haven't decided which one) from Adelaide to Cape Bernoulli and thence on to Twofold Bay (except it won't get there -- once far enough into the outback, the skyjacker Tom Ayerton will fake mechanical trouble to cause a forced landing at a deserted airstrip, and then will take off without you); then on foot to a nearby airfield (haven't decided which one), crossing a whitewater river in a rowboat along the way (this will probably require additions to the source code to simulate the river flow); then in an ultralight or a Piper Cub to Twofold Bay and then on to Canberra; then in a DC-3 from Canberra to Auckland (except you'll have to force-land on a beach NW of Auckland instead); then in the trunk of a car driven by terrorists, to an undisclosed location; then on foot while escaping the terrorists to Auckland; and finally in a flying boat from Auckland to Tabor Island and back to Auckland to complete the mission. 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 22:52, 29 September 2016 (UTC)

Long-range aircraft

Are there now, or were there ever, aircraft which had transoceanic range and either (1) amphibious capability or (2) STOL/VTOL capability, or both? (By transoceanic range I mean specifically the range needed to fly from Auckland to the (supposed) location of the (not really existent) Tabor Island, and then either return to Auckland or fly on to Concepcion.) 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 03:16, 28 September 2016 (UTC)

Do airships count? ←Baseball Bugs ^{What's up, Doc?} carrots→ 06:03, 28 September 2016 (UTC)

No, because they cannot land without people on the ground helping to moor the airship. 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 06:40, 28 September 2016 (UTC)

"Minimal ground crew are required: two for an Airlander 10 and none for an Airlander 50." -- https://www.hybridairvehicles.com/downloads/download/Airlander%20Student%20Q&A%20Sheet.pdf

Well, now that I let the cat out of the bag (see below), here's the real reason why airships don't count: because they are not simulated in FSX except as AI traffic! 2601:646:8E01:7E0B:8066:7A88:8D1A:2A2B (talk) 00:26, 29 September 2016 (UTC)

I don't believe any such aircraft has ever existed. The closest you might come is the Martin JRM Mars, a large flying boat introduced in the waning days of World War II; it had maximum range of nearly 5,000 miles but it did not have amphibious capability. That combination of capabilities is a very tough one to engineer; the sheer thrust required for VTOL and the high-lift wings required for STOL tend to impose severe penalties on an aircraft's cruise performance. However, if you're trying to come up with something for a work of fiction, it's probably not too great a leap to postulate a version of the JRM Mars that would be equipped with amphibious landing gear. It was done on the smaller Consolidated PBY Catalina. NorthBySouthBaranof (talk) 07:53, 28 September 2016 (UTC)

Darn, I was hoping there was at least one. So did the Mars (or any other flying boat) have the ability to fly from Auckland to the (supposed) location of the (non-existent) Tabor Island and then either return to Auckland or fly on to Concepcion without refueling? 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 07:55, 28 September 2016 (UTC)

According to NOAA's lat-long distance calculator, the great circle distance between Auckland and "Tabor Island" is 2,308 nautical miles, so a round-trip would be 4,616 nm; that would be slightly more than the reported 4,300 nm range of the Mars, but within the realm of plausibility (auxiliary fuel tanks?) NorthBySouthBaranof (talk) 08:03, 28 September 2016 (UTC)

How did you get 2,308 miles? Did you use the 1900 coordinates for the "island", or the 1983 ones? 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 08:18, 28 September 2016 (UTC)

The 1983 one listed at Maria Theresa Reef - 36°50′S 136°39′W. Auckland coordinates used were 36°50 S, 174°44 E. NorthBySouthBaranof (talk) 08:32, 28 September 2016 (UTC)

I see. Of course, since the island doesn't really exist, the old coordinates would do just as well as the new ones ;-) and that would be a lot better for me (because then the "island" would be well within roundtrip range from Auckland). Thanks! 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 09:02, 28 September 2016 (UTC)

Aha, perfect! You're welcome :) NorthBySouthBaranof (talk) 15:30, 28 September 2016 (UTC)

The Spruce Goose was designed to fly across the Atlantic and land on the water. I'd imagine people with access to aluminum can do better; on the other hand, I'd think the Goose might have been mothballed for a reason. Wnt (talk) 09:52, 28 September 2016 (UTC)

Would agree with you that this was mothballed for a reason. This is strictly OR. Having watched the first and only maiden flight of the Spruce Goose, Howard Hughes (who was the designer, expert on aircraft and whom piloted it) must have realized that the wings were flapping too much. Thus, was not a viable aircraft, so no point in flying it again. Does not matter whether is wood or aluminum though. Boeing had the same problem with the prototypes of the Jumbo 747 with its extended wingspan. By then however, the knowledge of tuned mass dampers came to their rescue. Modern aircraft use either very heavy iron-nickel weights and even depleted uranium in their wings to dampen out the resonance.--Aspro (talk) 15:18, 28 September 2016 (UTC)

You piqued my interest and I found film at [8] - certainly I'm in no position to comment on how much the wings move simply by looking at that ... but man, that's not much of a flight, is it? Part of my confusion is that for any other jet landed in water, "ditching" is considered close kin to suicide, and if someone actually does it right they make a movie about his incredible skill. I guess though from reading the article that the Goose had a remarkably slow (250 mph) cruising speed... maybe that means a slower stall speed? It's all very mysterious. There's some incredible story here but I'm unlikely to guess what it is. Wnt (talk) 16:56, 28 September 2016 (UTC)

Wnt says "any other jet", but the Spruce Goose was not a jet. I believe there were some successful emergency landings of propeller airliners (not designed for it) in water, though I don't have specifics. --69.159.61.230 (talk) 23:05, 28 September 2016 (UTC)

Wait, where did I ever say that it has to be a jet? All I said is that it must be able to either land on water, or on a dime. 2601:646:8E01:7E0B:8066:7A88:8D1A:2A2B (talk) 00:18, 29 September 2016 (UTC)

I think you're missing the point. 69 isn't saying you said it has to be a jet. 69 is saying Wnt comparisons are flawed since they are thinking of jets but the Spruce Goose isn't one. Nil Einne (talk) 03:52, 29 September 2016 (UTC)

Erm, yah. I was thinking "big honking airplane", not truly a jet, sorry. But that's probably a big part of the answer, I'm sure the stall characteristics for propellers vs jets must be vastly different... Wnt (talk) 02:14, 30 September 2016 (UTC)

They are -- a prop plane can "hang on the props" (create a slipstream of air over the wings with the props to increase lift and reduce stall speed), but a jet cannot. Also, most jets have swept wings, which create all sorts of high-alfa effects which don't happen with straight wings (tip-stall, forward center-of-lift shift, etc.) Whereas with delta wings it's completely different still -- at a high alfa you get leading-edge vortices, which boost lift but also create a yuuuge induced drag -- so you can pull the nose way up without stalling, but in this attitude you'll bleed off airspeed like crazy and end up with a downright frightful sink rate. 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 12:22, 30 September 2016 (UTC)

There are several VTOL fighter aircraft, which effectively have unlimited range with aerial refueling. For what purpose are you asking? --47.138.165.200 (talk) 21:28, 28 September 2016 (UTC)

Well, a fighter plane simply won't do for this, with or without aerial refueling -- this is for an idea I had for a FSX mission (loosely) based on one of Jules Verne's most famous novels (hence the question specifically about Tabor Island, even though it doesn't actually exist and would have to be created as a scenery add-on). And you can't very well bring the Captain back to Auckland in a Harrier jet, especially since you'll also have to fly your copilot Major McNabbs back at the same time, right? 2601:646:8E01:7E0B:8066:7A88:8D1A:2A2B (talk) 00:18, 29 September 2016 (UTC)

If it's Jules Verne themed, then you could assume that on the island they've managed to somehow assemble an oil refinery on the island (some of their actual feats in The Mysterious Island are nearly as miraculous), in which case an V-22 Osprey will just do it - ferry range of 2,230 mi, while the distance you want cover is around 2,000 mi. Smurrayinchester 09:35, 29 September 2016 (UTC)

But where would they find the oil? Besides, in FSX fuel is only found at airports. 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 11:58, 29 September 2016 (UTC)

The Martin P6M SeaMaster was an experimental jet-powered flying-boat bomber in the 1950s. The quoted range with a combat load was 1,810 nautical miles (just over 2,000 statute miles) but most aircraft have a "ferry range" which is rather longer. Alansplodge (talk) 12:04, 29 September 2016 (UTC)

GlobalSecurity.org - P6M SeaMaster says "Ferry range is estimated to have been about 3500 miles". Three prototype aircraft were flying when the project was cancelled in 1959, because the Polaris missile system was deemed to be less vulnerable. Alansplodge (talk) 14:53, 29 September 2016 (UTC)

Hey, I've had an idea -- instead of a flying boat, why not take the Russian Ekranoplane (which is already present as an AI traffic object in the "Tokyo Executive Transport" and "Aleutian Cargo Run" missions) and adapt it for use as a piloted aircraft? 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 04:50, 30 September 2016 (UTC)

However, the biggest ekranoplane, the Caspian Sea Monster, had a range of only 1,500 km (932 miles). Alansplodge (talk) 10:14, 30 September 2016 (UTC)

Oh, does it? Then I guess a flying boat is the only choice. 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 12:12, 30 September 2016 (UTC)

Olympus engine

Was the Olympus 593 engine susceptible to flameout due to water ingestion (as in, during hurricane conditions)? 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 05:52, 28 September 2016 (UTC)

Highly unlikely. Large turbine engines for aircraft must be demonstrated to be tolerant of ingestion of ice and water. I don't know exactly what requirements were applied to the Concorde or the Olympus 593, but the current US requirements for supersonic aircraft can be seen here: FAR 33.78(c). It is most likely the requirements applied to the Olympus 593 were not significantly different to these.

The current US requirements defining the atmospheric conditions and size of rain and hail can be seen here: FAR 33, Appendix B. Dolphin (t) 13:25, 30 September 2016 (UTC)

Darn, this means I'll have to make something up :-( Thanks anyway! 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 23:06, 30 September 2016 (UTC)

Are you writing a novel? You could say a mysterious problem occurs in the control system for the engine intake ramps on two adjacent engines, causing overheating and substantial loss of thrust. The flight crew then shut down both these engines as a precautionary measure. The aircraft can no longer maintain Mach 2.0 so they must descend to 35,000 feet where they run into bad weather. The possibilities are endless! Dolphin (t) 06:01, 1 October 2016 (UTC)

Nope -- this is not for a novel, this is for a FSX mission based on one (see above). And the triple engine failure (one of the engines will have already failed) is supposed to occur on final to Adelaide, when the plane has already been flying through the hurricane for some time. (I can just imagine the flight engineer saying, "It looks like we're going swimming -- enzhoy it!") 2601:646:8E01:7E0B:F88D:DE34:7772:8E5B (talk) 07:09, 1 October 2016 (UTC)

Closing the eyes of a corpse

In films and on TV we often see a character closing the eyes of a corpse. Can this actually be done? How hard is it? Do they stay closed? DuncanHill (talk) 23:58, 28 September 2016 (UTC)

I believe it's often easy to do before rigor mortis sets in, and they're more likely to stay closed even after, if done before, one reason it should ideally be done soon after death. However they may not stay closed so using tape or other methods like placing something over the eyelids to hold them closed is often recommended if possible and done with care. Also, even if this is done, they may still open, at least slightly, later. [9] [10] [11] [12] [13] [14]. Morticians have adhesives and other methods to ensure the eyes stay closed [15] although this source recommends against doing that or using excessive force if dealing with it by yourself due to the risk of easily visible damage [16]. If my personal memory is correct, it's very difficult to close the eyelids during rigor mortis if they are left open or re-open (which isn't surprising), although this is only a single case. Note that not everyone dies with their eyes open [17]. Edit: This source [18] mention trying to lift the eyelids is one way test for rigor mortis, probably mostly because it's first detected there. See also [19] Nil Einne (talk) 03:59, 29 September 2016 (UTC)

Thank you - that seems to cover it pretty comprehensively! DuncanHill (talk) 08:53, 29 September 2016 (UTC)